Stent loading and delivery device having a loading basket lock mechanism

ABSTRACT

A stent loading and delivery system, the delivery system comprising an inner elongate tubular member having a proximal end and a distal end, an intermediate elongate tubular member having a proximal end and a distal end in sliding relationship to said inner elongate tubular member and an external elongate tubular member having a proximal end and a distal end in sliding relationship to said intermediate elongate tubular member, said intermediate elongate tubular member comprising a stop mechanism at its proximal end, wherein the stop mechanism prevents the external elongate tubular member from being slid past the stop mechanism when the external elongate tubular member is slid in a proximal direction.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.14/540,492, filed Nov. 13, 2014, which is a continuation of U.S. patentapplication Ser. No. 13/328,023, filed Dec. 16, 2011, which claimspriority to U.S. Patent Provisional Application No. 61/428,261 filedDec. 30, 2010, the entire contents of which are hereby incorporatedherein by reference.

BACKGROUND OF THE INVENTION

The present invention relates to an assembly for loading and deliveringa stent.

An intraluminary prosthesis is a medical device used in the repairand/or treatment of diseases in various body vessels, for example, astent. Stents are generally cylindrical shaped devices that are radiallyexpandable to hold open a segment of a blood vessel or other anatomicallumen after implantation into the body lumen. For example, stents may beused in the coronary or peripheral vasculature, esophagus, trachea,bronchi colon, biliary tract, urinary tract, prostate, brain, as well asin a variety of other applications in the body. These devices areimplanted within the vessel to open and/or reinforce collapsing orpartially occluded sections of the lumen.

Stents may be formed of metallic materials as well as polymeric andbiodegradable materials, either in total or in part. In many procedures,polymeric or bioabsorbable prostheses are preferred over metallicdevices, for example, due to the relative ease of removing a deviceintended for temporary implantation, or the capacity to be absorbed intothe body.

When maintained in the reduced-radius state under a constant load forany appreciable length of time, a prosthesis formed of polymeric orbioabsorbable material may, however, undergo permanent or plasticdeformation. When released from the catheter or other delivery device,such prosthesis may radially self expand to a diameter considerably lessthan its relaxed-state diameter prior to preloading. This phenomenon iscommonly referred to as stress relaxation or “creep”. This phenomenon isaggravated when a polymeric or bioabsorbable prosthesis is exposed toelevated temperatures in its reduced-radius state, for example during asterilization procedure, which may be performed prior the outset of theprosthesis deployment procedure.

To counteract this phenomenon of stress relaxation or creep, thepolymeric or bioabsorbable prosthesis may be sterilized and/or stored inits relaxed state, i.e., not significantly reduced radial state, untiljust before it is to be used. When the physician is about to begin aprocedure, he or she may load the polymeric prosthesis into the deliverysystem. Consequently, the prosthesis remains compressed in thereduced-radius state only for a short time, perhaps only severalminutes. While such a procedure counteracts the problem of creep, theprocedure is, however, more difficult and time consuming. Although it iscommon practice to load a stent into a sheath during assembly of a stentdelivery system, such loading often involves numerous steps and oftenrequires the use of multiple components (e.g., tools and fixtures) thatare not part of the stent delivery system. For example, currentlyavailable stent delivery systems often require that a stent be loadedonto a delivery system by means of a funnel, basket or other similardevice which are not part of the delivery system.

There remains a need in the art for an improved stent loading devicethat is permanently attached to a stent delivery system to allow loadingof a stent into stent delivery systems at the time of use, whileminimizing the risk of damaging the stent in the process.

SUMMARY OF THE INVENTION

The present invention is directed to a method and system for deliveringa self-expanding stent into a body lumen. In particular, the presentinvention relates to an assembly and a method for loading and deliveringa stent in combination with a stent delivery catheter device, as well asto overall stent delivery systems.

In one embodiment, the present invention relates to a stent loading anddelivery system, the delivery system including an inner elongate tubularmember having a proximal end and a distal end, an intermediate elongatetubular member having a proximal end and a distal end in slidingrelationship to said inner elongate tubular member and an externalelongate tubular member having a proximal end and a distal end insliding relationship to said intermediate elongate tubular member, saidintermediate elongate tubular member comprising a stop mechanism at itsproximal end, wherein the stop mechanism prevents the external elongatetubular member from being slid past the stop mechanism when the externalelongate tubular member is slid in a proximal direction.

In one embodiment, the present invention relates to a stent loading anddelivery system including an inner elongate tubular member having aproximal end and a distal end, the inner elongate tubular member havinga proximal handle at the proximal end, an intermediate elongate tubularmember in sliding relationship to the inner elongate tubular member, theintermediate elongate intermediate member having a proximal end and adistal end, the intermediate elongate tubular member having anintermediate handle, the intermediate handle having a first position anda second position, in the second position the intermediate handle isadjacent the proximal handle, an external elongate tubular member havinga proximal end and a distal end, the external elongate tubular memberoverlying at least a portion of the intermediate elongate tubularmember, the external elongate tubular member having a distal handle atthe proximal end of the external elongate tubular member, the distalhandle having a proximal position and a distal position and a stopmechanism secured to the proximal end of the elongate intermediatemember at a point corresponding to the proximal position of the distalhandle of the elongate external tubular member, the stop mechanismhaving a first unexpanded state and a second expanded state wherein whenthe distal handle of the external elongate tubular member is in theproximal position, the proximal end of the external elongate tubularmember overlies the stop mechanism and the stop mechanism is in itsunexpanded state and when the distal handle of the external elongatetubular member is in the second distal position the stop mechanism isexposed and is in its expanded state, the stop mechanism preventing thedistal handle from moving to a point beyond the stop mechanism.

The device may further include a stent loading basket having opposedproximal and distal ends. In some embodiments, the proximal end may besecurely disposed to the distal end of the intermediate elongate tubularmember. The stent basket may have a truncated-conical shape, outwardlydiverging in a distal direction from its proximal end. The stent basketmay be a thin film which can collapse such that the stent basket may beslidably contained within the external member, or may be a radiallydistensible member which can collapse such that the stent basket may beslidably contained within the external member. In some embodiments, thestent basket may be composed of a polymeric material. The stent basketmay include, in part or substantially, braided polymeric filaments. Thebraided filaments may be contained within a thin polymeric film. Theintermediate member may be an elongate tubular device. The stent basketmay comprise metals, polymers, or combinations of both.

In another embodiment, the present invention relates to A stent loadingand delivery device including at least one inner tube having a proximalend and a distal end and a stop mechanism located at the proximal endand at least one outer tube having a proximal end and a distal end, theouter tube in sliding relationship with said at least one inner tube,the stop prevents the outer tube from advancing proximally when theproximal end of the outer tube is adjacent the stop.

The method of utilizing the system for stent loading and delivery isalso contemplated herein.

These and other aspects, embodiments and advantages of the presentdisclosure will become immediately apparent to those of ordinary skillin the art upon review of the Detailed Description and Claims to follow.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side view of an embodiment of a stent loading and deliverydevice according to the invention prior to stent loading.

FIG. 2 is a side view of an embodiment of a stent loading and deliverydevice similar to that shown in FIG. 1 wherein the stent and stentloading basket have been loaded into the distal end of the externalelongate tubular member.

FIG. 3 is a side view of an embodiment of a stent loading and deliverydevice similar to that shown in FIGS. 1 and 2 wherein the stent has beendeployed and the stent loading basket remains in the distal end of theexternal elongate tubular member.

FIG. 4 is an embodiment of a stop mechanism according to the invention.

FIG. 5A is an alternative embodiment of a stop mechanism according tothe invention prior to expansion.

FIG. 5B is an embodiment of a stop mechanism similar to that shown inFIG. 5A in an expanded state.

FIG. 6A is an alternative embodiment of a stop mechanism according tothe invention in an unexpanded state.

FIG. 6B is an embodiment of a stop mechanism similar to that shown inFIG. 6A in an expanded state.

FIG. 6C is an embodiment of a stop mechanism similar to that shown inFIGS. 6A and 6B in an expanded state with the distal handle of theexternal elongate tubular member adjacent thereto.

FIG. 7 is a partial view of an intermediate member showing analternative embodiment of a stop mechanism in the form of a compressiblebump.

FIG. 8A is partial view of an intermediate member showing an alternativeembodiment of a stop mechanism in an unexpanded state wherein stopmechanism is disposed on the intermediate member and in the handleportion.

FIG. 8B is a partial view of an intermediate member showing a stopmechanism similar to that shown in FIG. 8A in an expanded state.

DETAILED DESCRIPTION OF THE INVENTION

While embodiments of the present disclosure may take many forms, thereare described in detail herein specific embodiments of the presentdisclosure. This description is an exemplification of the principles ofthe present disclosure and is not intended to limit the disclosure tothe particular embodiments illustrated.

As shown in the drawings and described throughout the followingdescription, as is traditional when referring to relative positioning onan object, the term “proximal” refers to the end of the apparatus thatis closer to the user and the term “distal” refers to the end of theapparatus that is further from the user. The distal end in the operativeposition is located within the patient's body and the proximal end inthe operative position is located outside the patient's body.

The present application is directed to stent loading and delivery deviceincluding an inner elongate tubular member, an intermediate elongatetubular member having a stop mechanism located on its proximal end andan external elongate tubular member. The system may further include astent loading basket wherein the proximal end of a stent is disposed andheld therein in an expanded or non-contracted state. The stent loadingbasket and stent can be loaded into the external elongate tubular memberbetween the external member and the inner elongate tubular member and isheld adjacent to the loading basket but no longer disposed therein. Whenthe stent is deployed using the external elongate tubular member, a stopmechanism incorporated with the intermediate elongate tubular memberprevents the loading basket from being deployed from within the externalelongate tubular member. The device will be described in detail withrespect to the drawings below.

The method of utilizing the stent loading and delivery device is alsocontemplated by the present invention. In some embodiments, theutilization may include a method for loading, delivery and deployment ofa stent utilizing the system in percutaneous, transluminal or otherinsertion techniques. The device allows the practitioner to easily loada stent into the delivery system with minimal effort and withoutdamaging the stent.

Turning now to the figures, FIG. 1 is a cross-sectional view of a stentloading and delivery system 100 according to the present invention. Thesystem 100, as depicted, may be particularly well suited for loading,transluminal delivery and intraluminal deployment of a radiallyself-expanding prosthesis, such as a stent and/or a stent-graft. Thesystem 100 may include a catheter-type device with three elongatedcylindrical members concentric about an axis and having opposed proximaland distal ends. The three members can be structured as follows: Aflexible inner elongate tubular member 120, an intermediate elongatetubular member 140 slidably containing the inner member 120 therein, andan external elongate tubular member 160 slidably containing theintermediate member 140 therein.

Stent loading basket 200 is secured to the distal end of theintermediate member and lies adjacent the distal end of the externalmember and holds stent 300 in an unconstrained state therein.

Each member 120, 140, 160 of the system 100 may be controlled at theproximal end by a respective handle as follows. A proximal handle 130may be fixedly disposed at the proximal end 117 of the inner member 120,handle 150 may be disposed at the proximal end 137 of the intermediatemember 140 and handle 170 may be disposed at the proximal end 157 of theexternal member 160. Handle 170 is shown disposed furthest away from thepractitioner in relation to other handles or away from the proximal end117 of the inner member 120 in this embodiment. The intermediate handle150 may be disposed between the distal handle 170 and the proximalhandle 130, which may be disposed closest to the practitioner.

Handles 130, 150, and 170 are displaceable along the longitudinal axis98 relative to each other thereby enabling selective deployment andretraction of the stent 300. Manipulation or axial movement of thehandles 130, 150 and 170 permits independent axial movement of thetubular members 120, 140, and 160, respectively. For example, handle 150may slide between a distal position 151 shown in FIG. 1 and a proximalposition 153 shown in FIG. 2 so as to axially move the intermediatemember 140. Such movement may be done while keeping the other handles130, 170 fixed or relatively fixed to allow independent or substantiallyindependent movement of the intermediate member 140. While theintermediate member 140 is moved, the inner member 120 and the externalmember 160 may remain fixed or relatively fixed.

Handle 170 is fixedly attached to the distal end 157 of external member160 and moves proximally and distally between first and second positions171 (proximal), 173 (distal).

When handle 170 is moved from proximal position 171 to distal position173 stent loading basket 200 which engages and secures a proximal end ofstent 300 is compressingly loaded along with stent 300 into the distalend 161 of the external tubular member 160 and holds the stent in acollapsed and constrained position over the inner tubular member 120 asshown in FIG. 2.

The intermediate handle 150 is moved from a distal position shown at 151in FIG. 1 to a proximal position 153 adjacent handle 130 as shown inFIG. 2. This seats the stent 300 immediately adjacent stent loadingbasket 200 with the proximal end of the stent 300 no longer withinloading basket 200 as shown in FIG. 2.

During the loading of the stent 300, the handles 170 and 150 may be keptfixed in relatively constant axial displacement from one and another. Assuch, the inner member 120 and the intermediate member 140 may also bekept in relative constant axial positions with the intermediate member140 being substantially disposed within the external member 160.However, the intermediate member 140 need not be completely containedwithin the external member 160. Rather, a portion of the distal end ofthe intermediate member 140 may be axially outside or distally disposedfrom the distal end of the external member 160.

An added feature may be a stent holder (not shown) which can be providedon a distal portion referred to as the stent engagement region 110 ofthe inner elongate tubular member 120 to temporarily hold the stent inplace without any substantial external force acting on it. The stentholder may be further defined by a tubular band (not shown). The stentholder may releasably hold stent 300 within system 100 even after thestent basket 200 may be axially displaced away from the stent 300. Suchfeature may allow, if desired, for a large portion of the stent 300 tobe deployed and then be recaptured or re-engaged by stent basket 200prior to complete deployment of the stent 300. The recapturing may beachieved by axially sliding the external member 160 over the stent 300.Moreover, the stent basket 200 may be repositioned between the innermember 120 and the external member 160, for example, by axiallyadvancing the stent basket 200 to reposition the stent 300 thereinbetween. Furthermore, the whole system 100 may be moved proximally ordistally to reposition the stent 300 therein. These features mayprovide, among other things, reloading ability (reconstrainability) ofthe stent 300 within the system 100 of the present invention. Thesefeatures are described more fully in US Patent Publication No.2009/0192518.

Thus, during delivery through a patient's body lumen, the stent 300 isreleasably secured in the stent deployment region 110 between the innerand outer tubular members 120, 160.

The stent delivery system 100 can now be positioned in the patient fordeployment of stent 300. Insertion of the distal end of the system 100into a patient's body is performed with a lead-in such as the distal endtip 240. Once the practitioner navigates the distal end tip 240 to adesired location, and is satisfied with the location and orientation ofthe partially deployed stent 300, the practitioner can actuate thehandle 170 to its proximal position 171 to release fully deploy thestent 300 from the deployment region 110 of the delivery system asdepicted in FIG. 3. The practitioner can then pull back the distalhandle 170 toward the intermediate handle 150, thereby pulling back theexternal member 160. This step uncovers the constrained stent 300 can beunloaded at the desired deployment site. The delivery system 100 canthen be removed from the body.

It should be noted that the stent loading and delivery device can beconfigured and arranged to allow a practitioner to re-load the stent inthe event that it is positioned at the wrong location within a patient.For example, the intermediate handle 150 may have a release mechanismsuch that the intermediate handle 150 can be repositioned back to theoriginal position if the stent 300 needs to be removed from the body andre-loaded. Optionally, the system can be positioned by axially moving orsliding the stent engaging basket 200 to a location past the stentdeployment region 110 for disengagement of the stent 300 from theintermediate member 140.

A device of this type can be found in US Patent Publication No.2009/0192518, the entire content of which is incorporated by referenceherein.

A stop mechanism 180 is located at and secured to the proximal end ofthe intermediate member 140 which corresponds to position 171 of handle170. When handle is at position 170 the external member 160 constrainsthe stop mechanism in a first collapsed position. As shown in FIGS. 2and 3, when the handle 170 is moved distally to position 173 the stopmechanism expands to form a conical flare at one end. When the handle170 is moved back to position 171 after stent deployment, the stopmechanism prevents the external member 160 from being retracted anyfurther and deploying stent loading basket 200 from the distal end 161of the external elongate tubular member. This prevents the catheterassembly from being reused for future procedures.

One embodiment of a stop mechanism 180 is shown in FIG. 4. In thisembodiment, the distal end of the stop mechanism comprises flanges 210which expand outwardly once the handle 170 is moved in a distaldirection to position 173.

An alternative stop mechanism 180 is shown in FIG. 5A (unexpanded state)and FIG. 5B (expanded state). The stop mechanism 180 is shown in theshape of a frustoconical cone having tabs or pleats 190 formed therein.

Yet another alternative design can be found in FIG. 6A (unexpandedstate), FIG. 6B (expanded state), and FIG. 6C (shown secured to theintermediate elongate tubular member 140 and adjacent to the distalhandle 170 of the elongate external tubular member 160 when the distalhandle 170 is in its proximal position again after stent deployment).This stops the external elongate tubular member 160 from being moved anyfurther proximally and prevents the loading basket 200 from beingdeployed from within the distal end 161 of the elongate external tubularmember 160 (also shown in FIG. 3). The stop mechanism 180 depicted inFIGS. 6A-6C is in the form of a tubular braid, much like a braidedstent.

In any of the above embodiments, the tubular members 120, 140, and 160may be formed of a biocompatible material such as a biocompatiblepolymer.

Examples of biocompatible polymers include, but are not limited to,polyolefins such as polyethylene (PE), high density polyethylene (HDPE)and polypropylene (PP), polyolefin copolymers and terpolymers,polyethylene terephthalate (PET), polyesters, polyamides, polyurethanes,polyurethaneureas, polypropylene and, polycarbonates, polyvinyl acetate,thermoplastic elastomers including polyether-polyester block copolymersand polyamide/polyether/polyesters elastomers, polyvinyl chloride,polystyrene, polyacrylate, polymethacrylate, polyacrylonitrile,polyacrylamide, silicone resins, combinations and copolymers thereof,and the like. Materials for the tubular members 120, 140, 160 may besame or different.

It should be noted that the stop mechanism 180, while shown as having aconical flare when expanded, can be anything that is covered by theexternal handle 160 upon loading, but is exposed when the handle 160 ismoved distally. The form of the stop mechanism 180 may include, but isnot limited to, a compressible bump, a raised portion on theintermediate member 140, a leaf spring, etc.

FIG. 7 is a partial view of intermediate member 140 illustrating analternative embodiment wherein the stop mechanism 180 is in the form ofa compressible bump or sleeve on the intermediate member 140.

FIGS. 8A and 8B illustrate yet another alternative embodiment whereinstop 180 is both disposed on the intermediate member 140 and in handleportion 170. FIG. 8A illustrates stop mechanism 180 in an unexpandedstate and FIG. 8B illustrates stop mechanism 180 in an expanded stateboth within handle 170 and on intermediate member 140.

Alternatively, the stop may be included on the handle portion 170 thatprevents proximal movement beyond the point shown in FIG. 3.

The tubular members 120, 140, and 160 may also have a surface treatmentand/or coating on their inner surface, outer surface or portionsthereof. A coating need not be applied to all of the tubular members120, 140, 160, and individual members may be coated, uncoated, partiallycoated, and the like. Useful coating materials may include any suitablebiocompatible coating. Non-limiting examples of suitable coatingsinclude, but are not limited to, polytetrafluoroethylene, silicone,hydrophilic materials, hydrogels, and the like. Useful hydrophiliccoating materials include, but are not limited to, alkylene glycols,alkoxy polyalkylene glycols such as methoxypolyethylene oxide,polyoxyalkylene glycols such as polyethylene oxide, polyethyleneoxide/polypropylene oxide copolymers, polyalkylene oxide-modifiedpolydimethylsiloxanes, polyphosphazenes, poly(2-ethyl-2-oxazoline),homopolymers and copolymers of (meth)acrylic acid, poly(acrylic acid),copolymers of maleic anhydride including copolymers of methylvinyl etherand maleic acid, pyrrolidones including poly(vinylpyrrolidone)homopolymers and copolymers of vinyl pyrrolidone, poly(vinylsulfonicacid), acryl amides including poly(N-alkylacrylamide), poly(vinylalcohol), poly(ethyleneimine), polyamides, poly(carboxylic acids),methyl cellulose, carboxymethylcellulose, hydroxypropyl cellulose,polyvinylsulfonic acid, water soluble nylons, heparin, dextran, modifieddextran, hydroxylated chitin, chondroitin sulphate, lecithin,hyaluranon, combinations and copolymers thereof, and the like.Non-limiting examples of suitable hydrogel coatings include polyethyleneoxide and its copolymers, polyvinylpyrrolidone and its derivatives;hydroxyethylacrylates or hydroxyethyl(meth)acrylates; polyacrylic acids;polyacrylamides; polyethylene maleic anhydride, combinations andcopolymers thereof, and the like. Additional details of suitable coatingmaterials and methods of coating medical devices with the same amongother features may be found in U.S. Pat. Nos. 6,447,835 and 6,890,348,the contents of which are incorporated herein by reference. Suchcoatings and/or surface treatment can be desirably disposed on theinside or a portion thereof of the external member 160 to aid, ifdesired, in loading and/or deploying of the stent.

The stent basket 200 may have a truncated-conical shape, being smallerat its proximal end, i.e., outwardly diverging in a distal directionfrom its proximal engaging end. The stent basket 200 may be a thin filmwhich can collapse such that the stent basket 200 may be slidablycontained within the distal end of the external member 160.Alternatively, the stent basket 200 may include a radially distensiblemember which can be collapsible such that the stent basket 200 can beslidably contained within the external member 160. For instance, thestent basket may be a porous tube, a flexible tube, or any otherconfigurable tube. In some embodiments, the stent basket 200 may be apolymeric member 200. The stent basket 200 may include, in part orsubstantially, braided filaments 206. The braided filaments 206 mayinclude polymeric filaments, metallic filaments and any other suitablefilaments. Alternatively, the braided filaments may be contained withina thin polymeric film.

The stop mechanism can be formed from any of a variety of flexiblematerials including polymer materials, flexible metals and shape memorymetals, and may be the same as or different than the intermediateelongate tubular member to which it is attached.

The stop mechanism is suitably integrated with the intermediate elongatetubular member using any suitable means known in the art such as byovermolding or applying heat to the interface once the stop mechanism isdisposed on the intermediate elongate tubular member such as by weldingor applying a laser.

Examples of flexible metals for forming the stop mechanism include, butare not limited to, stainless steel, aluminum and copper, for example.

Examples of polymer materials suitable for forming the stop mechanisminclude, but are not limited to, polyurethanes, polycarbonate andpolyesters, for example. Elastomeric polymer materials being preferred.

Examples of shape memory metals suitable for forming the stop mechanisminclude, but are not limited to, copper-zinc-aluminium-nickel,copper-aluminium-nickel, and nickel-titanium (NiTi) alloys, and can beformed from alloying zinc, copper, gold and iron. Nickel-titanium is apreferred shape memory metal.

Monofilaments available in a variety of polymeric materials includingnylon, polyethylene (UHMW), liquid crystal polymers, aramids such aspara-aramid, etc. can also be employed herein such as for making abraided stop. Flexible metals and shape memory metals can also beemployed in making a web or braid.

The device according to the invention is particularly suited for theloading and delivery of stents and stent/grafts.

These stents and stent/grafts find utility for vascular and non-vascularapplication. Non-limiting examples include, but are not limited to, thevasculature, gastrointestinal tract, abdomen, peritoneum, airways,esophagus, trachea, colon, rectum, biliary tract, urinary tract,prostate, brain, spine, lung, liver, heart, skeletal muscle, kidney,bladder, intestines, stomach, pancreas, ovary, uterus, cartilage, eye,bone, joints, and the like.

A particular example of a non-vascular application is for maintainingesophageal luminal patency in esophageal structures and occlusions ofthe concurrent esophageal fistulas.

Examples of esophageal stents which can be employed herein include, butare not limited to, the Polyflex® Esophageal Stent, a polyestersilicone-covered stent, the WallFlex® stent, WallStent®, and theUltraflex® stent which is a polyurethane covered Nitinol stent, allcommercially available from Boston Scientific/Microvasive, in Natick,Mass.

Stents sold under these tradenames and available from Boston Scientificare also available for use in the tracheobronchial system, the biliarytract, the duodenum and the colon, for example, and can also be usedwith these loading and delivery systems.

Most particularly, the stents employed herein are self-expanding stentsin all forms including, but not limited to, woven, knitted, braided,twisted, knotted, laser cut, welded, etc.

The description provided herein is not to be limited in scope by thespecific embodiments described which are intended as singleillustrations of individual aspects of certain embodiments. The methods,compositions and devices described herein can comprise any featuredescribed herein either alone or in combination with any otherfeature(s) described herein. Indeed, various modifications, in additionto those shown and described herein, will become apparent to thoseskilled in the art from the foregoing description and accompanyingdrawings using no more than routine experimentation. Such modificationsand equivalents are intended to fall within the scope of the appendedclaims.

All publications, patents and patent applications mentioned in thisspecification are herein incorporated by reference in their entiretyinto the specification to the same extent as if each individualpublication, patent or patent application was specifically andindividually indicated to be incorporated herein by reference. Citationor discussion of a reference herein shall not be construed as anadmission that such is prior art.

The invention claimed is:
 1. A stent loading and delivery system, thedelivery system comprising: an inner elongate tubular member having aproximal end and a distal end; an intermediate elongate tubular memberhaving a proximal end and a distal end, the intermediate elongatetubular member surrounding the inner elongate tubular member andlongitudinally slidable relative to the inner elongate tubular member;an outer elongate tubular member having a proximal end and a distal end,the outer elongate tubular member surrounding the intermediate elongatetubular member and longitudinally slidable relative to both the innerelongate tubular member and the intermediate elongate tubular member;the proximal end of the outer elongate tubular member movable distallyrelative to the intermediate elongate tubular member from a firstproximal position to a distal position, and then movable proximallyrelative to the intermediate elongate tubular member from the distalposition to a second proximal position, the second proximal positionlocated distal of the first proximal position; and a stop disposed onthe intermediate elongate tubular member; the stop movable between afirst configuration when the proximal end of the outer elongate tubularmember is in the first proximal position to a second configuration whenthe proximal end of the outer elongate tubular member is moved to thedistal position, and wherein the stop prevents movement of the proximalend of the outer tubular member back to the first proximal position fromthe distal position.
 2. The stent loading and delivery system of claim1, wherein the first configuration of the stop is an unexpanded stateand the second configuration of the stop is an expanded state.
 3. Thestent loading and delivery system of claim 1, wherein the inner elongatetubular member comprises a proximal handle at the proximal end of theinner elongate tubular member, the intermediate elongate tubular membercomprises an intermediate handle at the proximal end of the intermediateelongate tubular member, and the outer elongate tubular member comprisesa distal handle at the proximal end of the outer elongate tubularmember, wherein the outer elongate tubular member overlies the stop inthe first proximal position.
 4. The stent loading and delivery system ofclaim 3, wherein the distal handle is located distal of the stop in thesecond proximal position.
 5. The stent loading and delivery system ofclaim 1, wherein the stop permanently prevents the proximal end of theouter elongate tubular member from moving in a proximal direction to thefirst proximal position after the proximal end of the outer elongatetubular member is moved distally to the distal position.
 6. A stentloading and delivery system, the delivery system comprising: an innerelongate tubular member having a proximal end and a distal end; anintermediate elongate tubular member having a proximal end and a distalend, the intermediate elongate tubular member surrounding the innerelongate tubular member and longitudinally slidable relative to theinner elongate tubular member; an outer elongate tubular member having aproximal end and a distal end, the outer elongate tubular membersurrounding the intermediate elongate tubular member and longitudinallyslidable relative to both the inner elongate tubular member and theintermediate elongate tubular member; the proximal end of the outerelongate tubular member movable distally relative to the intermediateelongate tubular member from a first proximal position to a distalposition, and then movable proximally relative to the intermediateelongate tubular member from the distal position to a second proximalposition, the second proximal position located distal of the firstproximal position; a stop disposed on the intermediate elongate tubularmember; the stop movable between a first configuration when the proximalend of the outer elongate tubular member is in the first proximalposition to a second configuration when the proximal end of the outerelongate tubular member is moved to the distal position, and wherein thestop prevents movement of the proximal end of the outer tubular memberback to the first proximal position from the distal position; and astent loading basket secured to a distal end of the intermediateelongate tubular member and movable therewith.
 7. The stent loading anddelivery system of claim 6, wherein the stent loading basket extendsdistally of the distal end of the outer elongate tubular member when theproximal end of the outer elongate tubular member is at the firstproximal position.
 8. The stent loading and delivery system of claim 7,wherein the distal end of the outer elongate tubular member extendsdistally of the stent loading basket when the proximal end of the outerelongate tubular member is at the second proximal position.
 9. The stentloading and delivery system of claim 6, wherein the stent loading basketis in a radially expanded configuration when the proximal end of theouter elongate tubular member is at the first proximal position.
 10. Thestent loading and delivery system of claim 9, wherein the stent loadingbasket is radially constrained by the outer elongate tubular member intoa compressed configuration when the proximal end of the outer elongatetubular member is at the second proximal position.
 11. The stent loadingand delivery system of claim 6, wherein the stent loading basket isconfigured to surround a proximal end of a stent to load the stent ontothe inner elongate tubular member when the proximal end of the outerelongate tubular member is at the first proximal position.
 12. The stentloading and delivery system of claim 11, wherein the stent loadingbasket is prevented from surrounding a proximal end of a stent when theproximal end of the outer elongate tubular member is at the secondproximal position.
 13. The stent loading and delivery system of claim 6,further comprising an expandable stent having an unconstrained state anda constrained state and having a proximal end and a distal end, whereinthe proximal end of the stent is disposed within the stent loadingbasket.
 14. The stent loading and delivery system of claim 13, whereinwhen the proximal end of the outer elongate tubular member is in thedistal position the stent is in the constrained state within the distalend of the external elongate tubular member with the stent loadingbasket surrounding the proximal end of the stent.
 15. The stent loadingand delivery system of claim 14, wherein when the proximal end of theouter elongate tubular member is in the distal position and the stop isin the second configuration, the stent is distal of the outer elongatetubular member in the unconstrained state and the stent loading basketis within the outer elongate tubular member.
 16. A stent loading anddelivery system, the delivery system comprising: an inner elongatetubular member having a distal end and a proximal handle at a proximalend thereof; an intermediate elongate tubular member having a distal endand intermediate handle at a proximal end thereof, the intermediateelongate tubular member surrounding the inner elongate tubular memberand longitudinally slidable relative to the inner elongate tubularmember; an outer elongate tubular member having a distal end and adistal handle at a distal end thereof, the outer elongate tubular membersurrounding the intermediate elongate tubular member and longitudinallyslidable relative to both the inner elongate tubular member and theintermediate elongate tubular member; the distal handle of the outerelongate tubular member movable distally relative to the intermediateelongate tubular member from a first proximal position to a distalposition, and then movable proximally relative to the intermediateelongate tubular member from the distal position to a second proximalposition, the second proximal position located distal of the firstproximal position; and a stop disposed on the intermediate elongatetubular member; the stop movable between a first configuration when thedistal handle is in the first proximal position to a secondconfiguration when the distal handle is moved to the distal position,and wherein the stop prevents movement of the distal handle back to thefirst proximal position from the distal position.
 17. The stent loadingand delivery system of claim 16, wherein the first configuration of thestop is an unexpanded state and the second configuration of the stop isan expanded state.
 18. The stent loading and delivery system of claim16, wherein the distal handle is located proximal of the stop in thefirst proximal position, and the distal handle is located distal of thestop in the second proximal position.
 19. The stent loading and deliverysystem of claim 16, further comprising a stent loading basket secured toa distal end of the intermediate elongate tubular member and movabletherewith.
 20. The stent loading and delivery system of claim 19,wherein the stent loading basket extends distally of the distal end ofthe outer elongate tubular member when the distal handle is at the firstproximal position, and wherein the distal end of the outer elongatetubular member extends distally of the stent loading basket when thedistal handle is at the second proximal position.